Nervous Tissue and Communication

These flashcards cover vocabulary related to nervous tissue, its structure, and communication processes.

Glial cells

Supporting cells of neurons that help maintain homeostasis.

Tumors

Masses of cells dividing; do not necessarily indicate cancer.

Meninges

Protective coverings of the brain and spinal cord, consisting of three layers: dura mater, arachnoid mater, and pia mater.

Dura mater

The outermost layer of the meninges, not directly attached to the brain or spinal cord.

Myelination

The process of wrapping axons in myelin to increase the speed of nerve signal transmission.

Oligodendrocyte

A type of glial cell in the central nervous system that produces myelin.

Schwann cell

A type of glial cell in the peripheral nervous system that wraps around axons to form the myelin sheath.

Nodes of Ranvier

Gaps in the myelin sheath along an axon that facilitate the rapid transmission of nerve impulses.

Multiple sclerosis (MS)

A disease that affects the central nervous system by damaging the myelin sheath, leading to communication problems between the brain and the body.

Action potential

A rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane during nerve signal transmission.

Depolarization

The phase of an action potential where the membrane potential becomes more positive due to the influx of sodium ions.

Repolarization

The phase of an action potential that returns the membrane potential back to a negative value after depolarization.

Hyperpolarization

An increase in the membrane potential that makes the inside of the cell more negative.

Excitatory neurotransmitter

A neurotransmitter that increases the likelihood of the postsynaptic neuron firing an action potential.

Inhibitory neurotransmitter

A neurotransmitter that decreases the likelihood of the postsynaptic neuron firing an action potential.

Acetylcholine

A neurotransmitter involved in transmitting signals across the synapse between neurons and muscle cells.

Conduction velocity

The speed at which an electrical impulse travels along a nerve.

Saltatory conduction

The process by which action potentials jump from one node of Ranvier to another along a myelinated axon.

Synaptic transmission

The process of transferring information from one neuron to another at a synapse.

Neurotransmitter

Chemical substances that transmit signals across a synapse from one neuron to another.

Acetylcholinesterase

An enzyme that breaks down acetylcholine in the synaptic cleft to terminate the signal transmission.

Temporal summation

The process of multiple signals from one neuron occurring in quick succession that can lead to reaching the threshold for an action potential.

Spatial summation

The process of signals from multiple neurons contributing to reaching the threshold for an action potential.

Refractory period

The recovery phase after an action potential where the neuron cannot fire a new action potential.